Randomized controlled trial to evaluate the effect of canola oil on blood vessel function in peripheral arterial disease: rationale and design of the Canola-PAD Study

Abstract

Jennifer E Enns,1,2 Peter Zahradka,1–3 Randolph P Guzman,4,5 Alanna Baldwin,1 Brendon Foot,1 Carla G Taylor1–31Canadian Centre for Agri-Food Research in Health and Medicine, St Boniface Research Centre, Winnipeg, Canada; 2Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; 3Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; 4IH Asper Clinical Research Institute, St Boniface Hospital, Winnipeg, Canada; 5Section of Vascular Surgery, Department of Surgery, St Boniface Hospital, Winnipeg, CanadaBackground: Individuals with peripheral arterial disease (PAD) are at high risk for cardiac events due to atherosclerosis. Dietary fatty acid composition has been shown to modulate blood vessel properties, but whether a diet enriched in conventional canola oil can improve clinical endpoints in PAD is not known.Purpose: To describe the rationale and design of a clinical trial testing the effect of canola oil consumption on vascular function and cardiovascular risk factors in an 8-week dietary intervention in individuals with PAD.Methods: The Canola-PAD Study was a single center, prospective, double-blind, randomized controlled trial in 50 patients over 40 years old with PAD. Participants were randomized into two groups and consumed food items containing either conventional canola oil (25 g/day) or an oil mixture representing the Western diet (25 g/day) for 8 weeks as part of their usual diet. The primary outcome was vascular function (ankle-brachial index, arterial stiffness, endothelial dysfunction, walking capacity, and cognitive function). Secondary measurements included anthropometrics, serum lipid profile and fatty acid composition, markers of inflammation and glycemic control, and serum metabolite profile.Discussion: The Canola-PAD Study uses an innovative and noninvasive approach to evaluate the effect of canola oil on clinically relevant outcomes in individuals with PAD, including arterial stiffness, walking capacity, and cognitive function. The findings will help to inform clinical guidelines and recommendations for dietary fat intake. Keywords: peripheral arterial disease, ankle-brachial index, arterial stiffness, vascular function, cognitive function, canola oil